甜玉米自交系耐铝毒的初步筛选

Screen of aluminum toxicity tolerance in sweet corn inbred lines

酸性土壤铝毒是限制作物生产的主要因子之一,通过育种选育耐酸、耐铝的甜玉米(Zea mays L.)自交系是解决酸性土壤铝毒问题的有效途径之一,而确定耐酸铝的鉴定标准并筛选出耐性材料对耐铝毒育种有重要意义。试验采用营养液培养法,选取5个田间长势存在差异的甜玉米自交系对铝耐性进行鉴定,设0、0.1、0.2、0.3、0.4 mmol/L共5个Al3+浓度处理,分别于处理7、10、14 d后考察茎叶及根的鲜重和干重。结果表明,随处理浓度升高,甜玉米茎叶和根的生长均减慢,处理7和10 d的铝耐性鉴定结果相对一致,G107和G139表现为铝耐性最强,G118和G151对铝的耐性处于中间水平,G79对铝的耐受性最差。处理14 d后考察不同处理Al3+浓度下的过氧化物酶(POD)、过氧化氢酶(CAT)和超氧化物歧化酶(SOD)的活性发现,3种酶的活性在较低浓度下都有上升,之后随胁迫浓度的增大,3种酶的活性又均有所下降。

Aluminum toxicity is one of the major factors limiting crop production in acidic soils.Sweet corn(Zea mays L.)inbred lines breeding for aluminum toxicity tolerance is an effective way to solve this problem.To determine the identification method of aluminum toxicity tolerance and screen sweet corn lines with aluminum toxicity tolerance is of importance for aluminum toxicity tolerant breeding.5 sweet corn lines with different growth vigor were selected to identify the aluminum toxicity tolerance by nutrient solution culture.The concentrations of aluminum ions were 0,0.1,0.2,0.3 and 0.4 mmol/L,respectively.The fresh weight and dry weight of stems and leaf and root were measured on the 7th,10th and 14th day after treated by aluminum toxicity.The results showed that the growth of stem,leaf and root of sweet corn slowed down with the increase of treatment concentration,and the results of aluminum resistance test on the 7th and 10th day of treatment were relatively consistent,in which,G107 and G139 showed the best tolerance to aluminum toxicity,G118 and G151 were in the middle level,and G79 showed the worst tolerance to aluminum toxicity.The activities of POD,CAT and SOD were detected at 14th day after treated by different concentration of aluminum ions,that the activity of three enzymes increased at low concentration,and then decreased with the increase of stress concentration.